I already know of the stats you speak of, and it's not nothing. But as I explain below, on the scale of other pollutants and for how widespread it's usage is, it is a footnote. There are far bigger fish to fry first when it comes to reducing water usage and energy usage.

Lets look up some stats together. Most sources agree that we use about 4 trillion cubic meters of water every year worldwide (Although, this stat is from 2015 most likely, and so it will be bigger now). In 2022, using the stats here Microsoft used 1.7 billion gallons per year, and Google 5.56 billion gallons per year. In cubic meters that's only 27.48 million cubic liters. That's only 0.000687% of the worldwide water usage. Meanwhile agriculture uses 70%. Granted not every country uses 70%, but a 1% gain there overshadows any current and even future usage.

And even if we just look at the US, since that's where Google and Microsoft are based, which uses 322 billion gallons of water every day, resulting in about 445 billion cubic meters per year, that's still 0.00617%. So it's not hugely significant inside the US either, we can have 162 more Googles and Microsofts before we even top a single percentage.

There are plenty of other hobbies that are also terrible for the environment but we don't tackle them because like AI it would be a drop in the bucket. Honestly ask yourself, if AI was such a big issue and would threaten lives, why is nobody actually taking serious measures for it? Why are there no public campaigns to get people to stop using AI to save the water? It's because the stats are concerning, but not significantly so, and if the stats don't actually back up the position that AI usage is slowly sucking us dry, people don't stand behind it. If the advancement of AI allows us to save more lives through medical research, or allows us to farm more efficiently, it can easily pay back it's investment. And those things outweigh the negatives.

However, as I've stated multiple times below, I despise the wasteful usage of AI, and therefore you won't see me praising Bing or Google for their usage of AI in a way that makes no sense and just wastes resources. But the technology exists for everyone, not just those companies. There are more sustainable LLM models than GPT-4, and OpenAI can rightfully be criticized for not prioritizing efficiency rather that bigger and more power hungry models.

EDIT: Added US comparison